scholarly journals Not All Larvae Stay Close to Home: Insights into Marine Population Connectivity with a Focus on the Brown Surgeonfish (Acanthurus nigrofuscus)

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Jeff A. Eble ◽  
Luiz A. Rocha ◽  
Matthew T. Craig ◽  
Brian W. Bowen
Keyword(s):  
Resource Planning ◽  
Reef Fishes ◽  
Population Connectivity ◽  
Genetic Connectivity ◽  
Dispersal Ability ◽  
Small Range ◽  
Long Distance ◽  
Larval Recruitment ◽  
Marine Population ◽  
Acanthurus Nigrofuscus

Recent reports of localized larval recruitment in predominately small-range fishes are countered by studies that show high genetic connectivity across large oceanic distances. This discrepancy may result from the different timescales over which genetic and demographic processes operate or rather may indicate regular long-distance dispersal in some species. Here, we contribute an analysis of mtDNA cytochromebdiversity in the widely distributed Brown Surgeonfish (Acanthurus nigrofuscus;N=560), which revealed significant genetic structure only at the extremes of the range (ΦCT=0.452;P<.001). Collections from Hawaii to the Eastern Indian Ocean comprise one large, undifferentiated population. This pattern of limited genetic subdivision across reefs of the central Indo-Pacific has been observed in a number of large-range reef fishes. Conversely, small-range fishes are often deeply structured over the same area. These findings demonstrate population connectivity differences among species at biogeographic and evolutionary timescales, which likely translates into differences in dispersal ability at ecological and demographic timescales. While interspecific differences in population connectivity complicate the design of management strategies, the integration of multiscale connectivity patterns into marine resource planning will help ensure long-term ecosystem stability by preserving functionally diverse communities.

Multinational genetic connectivity identified in western Pacific hawksbill turtles, Eretmochelys imbricata

2018 ◽  
Vol 45 (4) ◽  
pp. 307 ◽  
Author(s):  
Ian Bell ◽  
Michael P. Jensen
Keyword(s):  
Great Barrier Reef ◽  
Conservation Management ◽  
Threat Assessment ◽  
Population Connectivity ◽  
Genetic Connectivity ◽  
Stock Structure ◽  
Barrier Reef ◽  
Long Distance ◽  
Eretmochelys Imbricata ◽  
Management Actions

Context An understanding of the genetic stock structure of wide-ranging marine species is necessary for sound conservation management. Eretmochelys imbricata is Critically Endangered globally, but is among the least studied marine turtles. Reduced population sizes, its long-distance migratory nature between feeding and nesting habitats and poor understanding of its stock structure, biology and anthropogenic impact(s) pose challenges to developing effective conservation strategies for regional conspecifics. Aims Quantification of the population connectivity between specific feeding areas and regional nesting populations is needed for threat assessment and development of mitigation actions. Methods Here, we sequenced the mitochondrial DNA (mtDNA) of 91 immature and adult foraging E. imbricata individuals captured at the Howick Group of islands in the far-northern section of the Great Barrier Reef (nGBR), Queensland, Australia. We used a Bayesian mixed-stock analysis (MSA) approach to determine the contribution of nine regional genetically characterised breeding populations to this feeding aggregation. Key results The MSA estimated that a majority (83%; 95% CI = 70–92%) of feeding E. imbricata had originated from nesting beaches in the Bismarck–Solomon Sea region, whereas only 15% (95% CI = 6–25%) had originated from nGBR rookeries. International reproductive migrations were also corroborated by the return of 18 uniquely numbered titanium flipper tags that had been applied to E. imbricata found foraging in the Howick Group and had swum to rookeries within the Bismarck–Solomon Sea region. These 18 turtles represent 86% of all migration tag–recaptures from the Howick Group. Conclusions We postulate that recent increases in nesting populations within the Solomon Islands may be due to the high level of protection afforded to foraging turtles within the Great Barrier Reef. Implications An understanding of the connectivity between specific feeding areas and nesting populations is necessary to determine threats to animals over their entire life history and, therefore, allow the development of sound conservation management actions.

scholarly journals Postglacial migration supplements climate in determining plant species ranges in Europe

2011 ◽  
Vol 278 (1725) ◽  
pp. 3644-3653 ◽  
Author(s):  
Signe Normand ◽  
Robert E. Ricklefs ◽  
Flemming Skov ◽  
Jesper Bladt ◽  
Oliver Tackenberg ◽  
...  
Keyword(s):  
Plant Species ◽  
Dispersal Ability ◽  
Potential Range ◽  
Small Range ◽  
Niche Modelling ◽  
Long Distance ◽  
Species Ranges ◽  
Postglacial Colonization ◽  
Current Climate ◽  
Postglacial Migration

The influence of dispersal limitation on species ranges remains controversial. Considering the dramatic impacts of the last glaciation in Europe, species might not have tracked climate changes through time and, as a consequence, their present-day ranges might be in disequilibrium with current climate. For 1016 European plant species, we assessed the relative importance of current climate and limited postglacial migration in determining species ranges using regression modelling and explanatory variables representing climate, and a novel species-specific hind-casting-based measure of accessibility to postglacial colonization. Climate was important for all species, while postglacial colonization also constrained the ranges of more than 50 per cent of the species. On average, climate explained five times more variation in species ranges than accessibility, but accessibility was the strongest determinant for one-sixth of the species. Accessibility was particularly important for species with limited long-distance dispersal ability, with southern glacial ranges, seed plants compared with ferns, and small-range species in southern Europe. In addition, accessibility explained one-third of the variation in species' disequilibrium with climate as measured by the realized/potential range size ratio computed with niche modelling. In conclusion, we show that although climate is the dominant broad-scale determinant of European plant species ranges, constrained dispersal plays an important supplementary role.

An unexpected new record of the Mediterranean orchid, Ophrys bertolonii (Orchidaceae) in Central Europe

Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Attila Molnár V ◽  
András Máté ◽  
Gábor Sramkó
Keyword(s):  
Central Europe ◽  
New Record ◽  
Dispersal Ability ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Permanent Establishment ◽  
Adriatic Coast ◽  
Northward Expansion ◽  
Mediterranean Plant

AbstractOne flowering specimen of Ophrys bertolonii (s. str.) — a plant with a Circum-Adriatic distribution and hitherto unknown in other regions — was found on 7th May 2010 in the vicinity of Kunadacs (Central Hungary; N 47°00′ E 19°17′). The nearest known populations of this Mediterranean plant inhabit the Adriatic coast (ca. 450 km away) in Croatia, therefore this new occurrence represents a significant long distance dispersal event. The circumstances of the occurrence argue against introduction, but we can not decide now whether this new appearance is temporary or permanent. The permanent establishment of this strictly entomophilous plant requires the presence of its specific pollinator in the close neighbourhood of the habitat. However, no pollination was observed on the three flowers of the plant until 9th May, and one day later the stem had disappeared most likely due to grazing. Whatever the long-term fate of the plant is, this discovery represents a significant long distance (jump) dispersal event, and testifies to the dispersal ability of Ophrys species. Additionally, the appearance of a mature Adriatic plant in Central Europe fits well into the currently observed, climate change driven northward expansion of European orchids, therefore this finding most likely reflects a growing Mediterranean-like climatic influence in the region.

scholarly journals Probability of successful larval dispersal declines fivefold over 1 km in a coral reef fish

2011 ◽  
Vol 279 (1735) ◽  
pp. 1883-1888 ◽  
Author(s):  
Peter M. Buston ◽  
Geoffrey P. Jones ◽  
Serge Planes ◽  
Simon R. Thorrold
Keyword(s):  
Larval Dispersal ◽  
Isolation By Distance ◽  
Dispersal Distance ◽  
Population Connectivity ◽  
Marine Ecology ◽  
Sea Anemones ◽  
Marine Population ◽  
Amphiprion Percula ◽  
Distance Distributions ◽  
Dispersal Distances

A central question of marine ecology is, how far do larvae disperse? Coupled biophysical models predict that the probability of successful dispersal declines as a function of distance between populations. Estimates of genetic isolation-by-distance and self-recruitment provide indirect support for this prediction. Here, we conduct the first direct test of this prediction, using data from the well-studied system of clown anemonefish ( Amphiprion percula ) at Kimbe Island, in Papua New Guinea. Amphiprion percula live in small breeding groups that inhabit sea anemones. These groups can be thought of as populations within a metapopulation. We use the x- and y -coordinates of each anemone to determine the expected distribution of dispersal distances (the distribution of distances between each and every population in the metapopulation). We use parentage analyses to trace recruits back to parents and determine the observed distribution of dispersal distances. Then, we employ a logistic model to (i) compare the observed and expected dispersal distance distributions and (ii) determine the relationship between the probability of successful dispersal and the distance between populations. The observed and expected dispersal distance distributions are significantly different ( p < 0.0001). Remarkably, the probability of successful dispersal between populations decreases fivefold over 1 km. This study provides a framework for quantitative investigations of larval dispersal that can be applied to other species. Further, the approach facilitates testing biological and physical hypotheses for the factors influencing larval dispersal in unison, which will advance our understanding of marine population connectivity.

Colonization of depopulated crinoids by symbionts: who comes from the bottom and who from the water column?

2015 ◽  
Vol 95 (8) ◽  
pp. 1607-1612 ◽  
Author(s):  
E.S. Mekhova ◽  
P.Y. Dgebuadze ◽  
V.N. Mikheev ◽  
T.A. Britayev
Keyword(s):  
Water Column ◽  
Field Experiments ◽  
Dispersal Ability ◽  
Long Distance ◽  
Sandy Substrate ◽  
Limited Dispersal ◽  
Set Up ◽  
Almost All ◽  
High Degree

Previous experiments with the comatulid Himerometra robustipinna (Carpenter, 1881) demonstrated intensive host-to-host migration processes for almost all symbiotic species both within host aggregations and among hosts separated by several metres. The aim of this study was to check the ability of symbionts to complete long-distance migrations, by means of two in situ experiments which depopulated the crinoid host. Two different sets of field experiments were set up: exposure of depopulated crinoids (set 1) on stony ‘islands’ isolated from native crinoid assemblages by sandy substrate, and (set 2) in cages suspended in the water column. Hosts from set 1 were exposed for 1, 2, 3 and 4 weeks to assess whether substrate has an influence on the symbionts' long-distance migrations. In set 2 cages were exposed for 10–11 days, aiming to check whether symbionts were able to disperse through the water column with currents. These experiments allow the conclusion that post-settled symbionts can actively migrate among their hosts. Symbionts are able to reach their hosts by employing two different ‘transport corridors’, by drifting or swimming in water column, and by moving on the bottom. Comparison of experimental results allows the division of symbionts into two conventional groups according to the dispersal ability of their post-settled stages: (1) species able to complete long-distance migrations, (2) species unable to migrate or having limited dispersal ability. The finding of the free-living shrimp Periclimenes diversipes Kemp, 1922 in set 2 raises the question about the factors that affect such a high degree of specialization of crinoid assemblages.

scholarly journals Observations of Long-distance Post-release Dispersal by Reintroduced Bison (Bison bison)

2018 ◽  
Vol 131 (3) ◽  
pp. 221-224 ◽  
Author(s):  
Thomas S. Jung ◽  
Nicholas C. Larter
Keyword(s):  
Site Fidelity ◽  
Performance Metrics ◽  
Survival Rates ◽  
Release Site ◽  
Bison Bison ◽  
Dispersal Ability ◽  
Initial Population ◽  
High Survival ◽  
Long Distance ◽  
Straight Line Distance

Key objectives of wildlife reintroduction projects should include encouraging post-release site fidelity and high survival rates of founding individuals. Yet, few studies empirically evaluate these performance metrics for released individuals. Bison(Bison bison) restoration is receiving renewed interest by wildlife managers. To inform new bison reintroduction projects, we provide an observation of a 375-km (straight-line distance) post-release movement of three bison bulls from a release site in Yukon, Canada, in 1988. In addition, we note 250-km and 155-km post-release movements of bison in the Northwest Territories, Canada, in 1980 and 1998, respectively. These observations demonstrate the dispersal ability of bison encountering new environments. Wildlife managers planning for new bison reintroductions should consider means to enhance post-release site fidelity to limit long-distance dispersal and mortality and maximize initial population growth.

scholarly journals First Observations of Long‐Distance Migration in a Large Skate Species, the Winter Skate: Implications for Population Connectivity, Ecosystem Dynamics, and Management

2019 ◽  
Vol 11 (2) ◽  
pp. 202-212 ◽  
Author(s):  
Michael G. Frisk ◽  
Oliver N. Shipley ◽  
Christopher M. Martinez ◽  
Kim A. McKown ◽  
Joshua P. Zacharias ◽  
...  
Keyword(s):  
Population Connectivity ◽  
Ecosystem Dynamics ◽  
Long Distance

scholarly journals Serial founder effects and genetic differentiation during worldwide range expansion of monarch butterflies

2014 ◽  
Vol 281 (1797) ◽  
pp. 20142230 ◽  
Author(s):  
Amanda A. Pierce ◽  
Myron P. Zalucki ◽  
Marie Bangura ◽  
Milan Udawatta ◽  
Marcus R. Kronforst ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Genetic Drift ◽  
North American ◽  
Range Expansion ◽  
Dispersal Ability ◽  
Founder Effects ◽  
Long Distance ◽  
Mobile Species ◽  
High Dispersal

Range expansions can result in founder effects, increasing genetic differentiation between expanding populations and reducing genetic diversity along the expansion front. However, few studies have addressed these effects in long-distance migratory species, for which high dispersal ability might counter the effects of genetic drift. Monarchs ( Danaus plexippus ) are best known for undertaking a long-distance annual migration in North America, but have also dispersed around the world to form populations that do not migrate or travel only short distances. Here, we used microsatellite markers to assess genetic differentiation among 18 monarch populations and to determine worldwide colonization routes. Our results indicate that North American monarch populations connected by land show limited differentiation, probably because of the monarch's ability to migrate long distances. Conversely, we found high genetic differentiation between populations separated by large bodies of water. Moreover, we show evidence for serial founder effects across the Pacific, suggesting stepwise dispersal from a North American origin. These findings demonstrate that genetic drift played a major role in shaping allele frequencies and created genetic differentiation among newly formed populations. Thus, range expansion can give rise to genetic differentiation and declines in genetic diversity, even in highly mobile species.

scholarly journals Incubation periods impact the spatial predictability of cholera and Ebola outbreaks in Sierra Leone

2020 ◽  
Vol 117 (9) ◽  
pp. 5067-5073 ◽  
Author(s):  
Rebecca Kahn ◽  
Corey M. Peak ◽  
Juan Fernández-Gracia ◽  
Alexandra Hill ◽  
Amara Jambai ◽  
...  
Keyword(s):  
Sierra Leone ◽  
Incubation Period ◽  
Population Connectivity ◽  
Disease Spread ◽  
Long Distance ◽  
Spatial Spread ◽  
Transmission Parameters ◽  
Incubation Periods ◽  
Using Data ◽  
The Impact

Forecasting the spatiotemporal spread of infectious diseases during an outbreak is an important component of epidemic response. However, it remains challenging both methodologically and with respect to data requirements, as disease spread is influenced by numerous factors, including the pathogen’s underlying transmission parameters and epidemiological dynamics, social networks and population connectivity, and environmental conditions. Here, using data from Sierra Leone, we analyze the spatiotemporal dynamics of recent cholera and Ebola outbreaks and compare and contrast the spread of these two pathogens in the same population. We develop a simulation model of the spatial spread of an epidemic in order to examine the impact of a pathogen’s incubation period on the dynamics of spread and the predictability of outbreaks. We find that differences in the incubation period alone can determine the limits of predictability for diseases with different natural history, both empirically and in our simulations. Our results show that diseases with longer incubation periods, such as Ebola, where infected individuals can travel farther before becoming infectious, result in more long-distance sparking events and less predictable disease trajectories, as compared to the more predictable wave-like spread of diseases with shorter incubation periods, such as cholera.

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